index.js

'use strict';
const nodes = require('nunjucks/src/nodes');

const NODE_KEYS = [
  'args',
  'arr',
  'body',
  'cond',
  'expr',
  'else_',
  'left',
  'name',
  'right',
  'target',
  'template',
  'val',
  'value',
];

const CHILD_KEYS = [
  'children',
  'ops',
  'targets',
];

const NODE_NAMES = Object.keys(nodes);

const getNodeType = (node) => {
  var type;
  return node.type || (NODE_NAMES.some((name) => {
    if (node.constructor === nodes[name]) {
      return type = name;
    }
  }), type);
};

const normalize = (node) => {
  return walk(node, n => {
    n.type = getNodeType(n);
  });
};

const clean = (node) => {
  return walk(node, n => {
    delete n.lineno;
    delete n.colno;
    delete n.parent;
  });
};

const walk = (node, func) => {
  if (func(node) !== false) {
    CHILD_KEYS
      .filter(key => Array.isArray(node[key]))
      .forEach(key => {
        node[key].forEach(child => walk(child, func));
      });

    NODE_KEYS
      .filter(key => node[key] && typeof node[key] === 'object')
      .forEach(key => walk(node[key], func));
  }
  return node;
};

module.exports = {
  clean: clean,
  normalize: normalize,
  getNodeType: getNodeType,
  walk: walk
};